Speed of light in air is 3×108 m/s and speed of light in common glass is 2×108m/s. Calculate the refractive index of glass

The refractive index of glass is 1.5.

To calculate the refractive index of glass, we use the formula:

Refractive Index (n) = Speed of Light in Vacuum (c) / Speed of Light in Medium (v)

Given:

• Speed of Light in Air (c): Approximately 3×10⁸ m/s (since the speed of light in air is almost equal to that in a vacuum)
• Speed of Light in Glass (v): 2×10⁸ m/s

Calculation:

n = 3 × 10m/s ÷ 2 × 10⁸ m/s

n = 1.5

So, the refractive index of glass is 1.5. This means that light travels 1.5 times slower in glass than in air (or vacuum). The refractive index is a measure of how much the speed of light is reduced inside a medium compared to a vacuum. A higher refractive index indicates a greater reduction in speed.